Repeaterless transmission enables less complex systems not only for submarine but also for terrestrial fiber optical communications. The fiber loss, fiber nonlinearities, and chromatic dispersion (CD) of the widely deployed standard single-mode fiber (SSMF) are the biggest hurdles to design and implement long-haul repeaterless terrestrial transmission systems operating at about 1550 nm. Previously, a record repeaterless transmission distance of 285 km over SSMF was reported using a chirped managed laser with low extinction ratio. However, this required careful selection of the combination of an appropriate dispersion compensating fiber, a switchable optical dispersion compensator, and electronic dispersion compensation. The present inventors recognized that the use of dispersion compensating fibers, and switchable optical dispersion compensators limit the repeaterless transmission distance of known fiber-optic communication systems.